In recent years, in order to record a high-definition image data, an optical information recording medium has been required to have a high information recording density. In order to respond to such a requirement, there has been developed a Blu-ray disc (BD-R) using a blue laser beam on a short-wavelength side in the vicinity of from 360 to 450 nm, for example, about 405 nm. An optical information recording medium having a structure in which an optical reflection layer and a recording layer are formed on the light incident surface side of a light transmission resin substrate and a light transmission layer is provided on the surface on which these optical reflection layer and recording layer are formed, or a structure in which the light transmission layer is provided via a protective layer is used. The recording layer of such an optical recording medium is constituted of an organic material including a dye such as an azo-based dye, a cyanine-based dye, etc., or an inorganic material such as a Te—Pd-based material, an Si—Cu-based material, a Ge—Bi-based material, etc., and data is recorded by forming pits upon laser irradiation for recording.
Also, in the foregoing optical information recording medium, for the purpose of further increasing its volume of recording information, there is proposed a multilayer type optical information recording medium having a plurality of recording layers.
For example, Patent Document 1 discloses an optical information recording medium in which a first substrate having a first information layer where at least a first recording layer composed of an organic dye and a semitransparent first reflection layer are accumulated and a second substrate having a second information layer where at least a second reflection layer and a second recording layer composed of an organic dye are stacked and fixed via a transparent interlayer such that the stacked layers are opposed to each other.
Also, Patent Document 2 discloses an optical information recording medium having a plurality of recording layers in the stacking direction on a substrate and being capable of undergoing recording and playback by a laser beam, wherein a reflection layer, a recording layer and a functional layer composed of SiO2 are stacked successively on the substrate; an interlayer is formed thereon; a semitransparent reflection film, a recording layer and a functional layer composed of SiO2 are further stacked successively on the interlayer.
Now, in an optical recording medium having a recording layer on the both surfaces thereof, such as DVD, etc., in place of a method for stacking transparent resin substrates having a reflection layer formed on the irregular surface with an adhesive in such a manner that the reflection layers are opposed to each other, there was conventionally provided a photocurable resin layer on a reflection layer of an optical disc substrate having a reflection layer (or a recording layer) on the irregular surface by means of coating. On the other hand, there is proposed a method in which a photocurable resin is provided on a stamper made of a polycarbonate by means of coating; thereafter, a substrate is face-reversed to bond the substrate and the stamper to each other; an ultraviolet ray is irradiated from the substrate side to cure the photocurable resin; and after curing, the stamper is removed, thereby forming a reflection layer (or a recording layer) and a cover layer on the irregular surface.
Also, in Patent Document 3, it is proposed to use a transfer sheet in place of the foregoing method for coating a photocurable resin. This method is concerned with a method in which a photocurable transfer sheet composed of a photocurable composition containing a reactive polymer having a photopolymerizable functional group and capable of being deformed upon pressurization is placed on the irregular surface of a substrate having irregularity as recording a pit and/or a groove on the surface thereof such that one of the surfaces thereof comes into contact with the irregular surface, these are pressed, and the photocurable transfer sheet is cured by ultraviolet radiation.
However, in the foregoing method using a transfer sheet, after the transfer sheet is cured, when the stamper is peeled off, a part of the photocured transfer layer of the photocurable transfer sheet often peeled off from the reflection layer such as a silver alloy, etc. and attached to the stamper. Then, in Patent Document 4, in a photocurable transfer sheet having a peeling sheet on both surfaces of a transfer layer, it is proposed to use a photocurable transfer sheet wherein when cured with an ultraviolet ray, one surface has a difference in a residual bonding rate of 3% or more from the other surface, thereby making it easy to peel from a stamper and increasing an adhesive power to a reflection layer.
However, all of these methods are concerned with DVD-ROM.    Patent Document 1: Japanese Patent Laid-open No. 2006-73086    Patent Document 2: Japanese Patent Laid-open No. 2005-243165    Patent Document 3: Japanese Patent Laid-open No. 2003-272244    Patent Document 4: Japanese Patent Laid-open No. 2007-185896